System and method for attaching soft tissue to bone

ABSTRACT

Disclosed herein are methods and devices for securing soft tissue to a rigid material such as bone. A bone anchor is described that comprises a base and a top such that suture material may be compressed between surfaces on the base and top to secure the suture to the anchor. Also described is an inserter that can be used to insert the bone anchor into bone and move the anchor top relative to the anchor base to clamp suture material there between. Also described is a soft-tissue and bone piercing anchor and associated inserter. Methods are described that allow use of the bone anchors to provide multiple lengths of suture material to compress a large area of soft tissue against bone.

RELATED APPLICATIONS

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 11/143,007 filed on Jun. 1, 2005 and which claimspriority to U.S. Provisional Application Nos. 60/576,477, filed on Jun.2, 2004; 60/610,924, filed on Sep. 17, 2004; and 60/634,174, filed onDec. 7, 2004; all of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical devices and procedures. Moreparticularly, the present invention relates to devices and methods forsecuring soft tissue to a rigid material such as bone.

2. Description of the Related Art

There are several medical procedures where a surgeon needs to attachsoft tissue such as tendons or other soft connective tissue to bone. Onecommon example is a torn rotator cuff, where the supraspinatus tendonhas separated from the humerus causing pain and loss of ability toelevate and externally rotate the arm. To repair a torn rotator cuff,typically a surgical procedure is used to suture the torn tendon to thebone using a variety of methods. Some procedures utilize large incisionsand involve complete detachment of the deltoid muscle from the acromion.Small diameter holes are made in the bone for passing suture materialthrough the bone to secure the tendon. Such large incision proceduresare traumatic, causing prolonged pain and recovery time. Otherprocedures make small incisions and use arthroscopic techniques toattach sutures using either small diameter holes or a bone anchor.However, it is difficult to manipulate sutures within the surgical siteusing arthroscopic techniques. In addition, when knot tying is used tosecure the suture to a bone anchor, it is difficult to properly adjustthe tension of the suture while tightening the knot. Similarly, when thesuture is attached to a bone anchor prior to insertion of the anchorinto the bone, it is difficult to judge the appropriate point ofattachment so that the suture will be properly tensioned upon insertionof the bone anchor into the bone. Thus, there is a need for methods anddevices that allow easy arthroscopic attachment of a suture to a boneanchor after the anchor is inserted into the bone without the use ofknot tying.

SUMMARY OF THE INVENTION

The present invention is particularly suited for use in arthroscopicprocedures, including but not limited to rotator cuff surgery. Morebroadly, it can be used in any procedure in which it is desired to fix asuture to a solid object without tying of knots, including not onlyarthroscopic procedures, but also open surgery, and can be used for suchdiverse purposes as bladder neck suspension, tendon and ligamentaffixation or repair, prosthetic attachment, and rotator cuff repair.

In one embodiment, the invention includes an anchor for securing asuture to bone, including an anchor base adapted to be securely fixedinto the bone and a suture securing mechanism coupled to the anchor baseand positioned proximally relative to the anchor base, the mechanismadapted to receive and secure a suture moved laterally into the

In another embodiment, the invention includes an anchor for securing asuture to bone, including an anchor base adapted to be securely fixedinto the bone, a first surface coupled to the anchor base and positionedproximally relative to the anchor base, and a second surface coupled tothe anchor base and positioned proximally relative to the anchor base,wherein the first and second surfaces are adapted to be relativelypositioned in at least two configurations, one of the configurationssuch that a gap is present between the first and second surfaces so thatthe suture can be positioned between the first and second surfaces bymoving the suture laterally into the gap, and the other of theconfigurations such that the first and second surfaces are in closeproximity so that the suture can be securely clamped between the firstand second surfaces.

In another embodiment, the invention includes a method of attaching softtissue to bone, including passing a length of suture over the softtissue, inserting an anchor into the bone, and securing the length ofsuture to the anchor after the inserting without passing an end of thelength of suture through any aperture in the anchor and without tyingany knots.

In another embodiment, the invention includes a method of attaching softtissue to bone, including inserting a first anchor through the softtissue, wherein the first anchor comprises a length of suture fixedlysecured to the first anchor prior to insertion, inserting the firstanchor into the bone, passing the length of suture over the soft tissue,and fixedly securing, after the passing, the length of suture to asecond anchor.

In another embodiment, the invention includes a method of attaching softtissue to bone, the soft tissue comprising a first surface adjacent tothe bone's surface and a second surface opposite the first surface, themethod including inserting a first portion of a length of suture intothe second surface of the soft tissue, passing a second portion of thelength of suture over the second surface of the soft tissue, inserting afirst anchor with no suture coupled thereto into the bone, and fixedlysecuring the length of suture to the inserted first anchor, with theproviso that no part of the first portion of the length of suture ispassed out of the second surface of the soft tissue.

In another embodiment, the invention includes a method of attaching softtissue to bone, including inserting a first anchor with a length ofsuture pre-coupled thereto through the soft tissue, inserting the firstanchor into the bone, inserting a second anchor with no suture coupledthereto into bone, passing the length of suture over the soft tissue,and fixedly securing the length of suture to the inserted second anchor.

In another embodiment, the invention includes a method of attaching softtissue to bone, the method including inserting a first, second, andthird anchor into the bone, fixedly securing a first length of sutureover the soft tissue to the first and second anchors, and fixedlysecuring a second length of suture over the soft tissue to the first andthird anchors.

In another embodiment, the invention includes an anchor for securing asuture to bone, the anchor including an anchor base adapted to besecurely fixed into the bone, the anchor base comprising a firstproximal surface and an anchor top, the anchor top comprising a distalmember coupled to the anchor base and a first proximal member comprisinga first distal surface, wherein the anchor top is adapted to couple tothe anchor base in at least two configurations, one of theconfigurations such that the first distal surface is above the bone'ssurface when the anchor base is securely fixed into the bone, such thata suture can be freely passed between the first proximal and firstdistal surfaces above the bone's surface, and the other of theconfigurations such that the first distal surface is in close proximityto the first proximal surface, such that a suture can be securelyclamped between the first proximal and first distal surfaces.

In another embodiment, the invention includes an anchor for securing asuture to bone, the anchor including a substantially hollow cylindercomprising an open end and comprising a portion of its walls cut in sucha manner so as to allow the cylinder to deform under stress and formlateral protrusions, a substantially pointed tip coupled to the cylinderopposite the open end, wherein the pointed tip is adapted to pierce thebone, and a suture receiver coupled to the pointed tip and positionedwithin the substantially hollow cylinder so that a suture may beattached to the suture receiver and extend through the cylinder and outof the open end.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts attaching soft tissue to bone using a single bone anchorand a stitch.

FIG. 2 depicts attaching soft tissue to bone using a two bone anchorswith a suture stretched there between.

FIGS. 3A-3C depict various geometries of bone anchors and suturepatterns for attaching soft tissue to bone.

FIGS. 4A-4D depicts the base of a two-part suture anchor that can beinserted into bone.

FIGS. 5A-5C depicts the top of a two-part suture anchor.

FIGS. 6A and 6B depict the suture anchor top of FIGS. 5A-5C insertedinto the suture anchor bottom of FIGS. 4A-4D.

FIGS. 7A and 7B depict a suture anchor inserter.

FIG. 8 depicts components on a suture anchor inserter for attaching tobone and manipulating a suture anchor.

FIGS. 9A-9E depicts manipulation of a suture anchor using a sutureanchor inserter to insert the suture anchor into bone and attach suturematerial to the suture anchor.

FIGS. 10A and 10B depict a piercing bone anchor in an un-deployed (FIG.10A) and deployed (FIG. 10B) state.

FIG. 11 depicts a piercing bone anchor tip.

FIG. 12 depicts an anchor inserter for inserting a piercing bone anchor.

FIG. 13 depicts the interface between a piercing bone anchor and ananchor inserter.

FIG. 14 is a cut-away view of a bone anchor inserter.

FIG. 15 depicts a safety switch mechanism for a bone anchor inserter.

FIGS. 16A-16F depict a method for attaching soft-tissue to bone using apiercing bone anchor and a suture capturing anchor.

DETAILED DESCRIPTION OF THE CERTAIN EMBODIMENTS

In various embodiments, soft tissue may be attached to bone utilizingone or more bone anchors with suture attached thereto. As used herein,“suture” refers to any flexible structure that can be stretched betweentwo or more anchors and includes, without limitation, traditional suturematerial, single or multiple stranded threads, or a mesh structure. Insome embodiments, suture is passed over the top of the soft tissue sothat the suture can press the soft tissue against the bone. In oneembodiment, a length of suture is attached to a single bone anchor. Onenon-limiting example, depicted in FIG. 1, includes stitching the suture10 to the soft tissue 12, such as by an incline mattress stitch, andthen securing the suture 10 to the single bone anchor 14 that isinserted into the bone 16. However, in other embodiments, a length ofsuture is attached to multiple bone anchors. The use of multiple boneanchors increases the footprint over which the suture material pressesthe soft tissue against bone. One non-limiting example, depicted in FIG.2, includes two bone anchors. One anchor 20 is positioned in a mediallocation underneath the soft tissue 12 and a second anchor 22 ispositioned lateral to the soft tissue 12. The suture 10 is attached toboth anchors.

In one embodiment, the suture 10 is attached to the lateral bone anchor22 only after the medial bone anchor 20 is inserted and the suture 10 ispassed over the soft tissue 12. In one embodiment, the suture 10 isattached to the medial bone anchor 20 prior to insertion of the medialbone anchor 20. Thus, in this embodiment, the surgeon does not need topass the suture through the soft tissue 12 from beneath the soft tissue12. In one embodiment, the procedure involves inserting the medial boneanchor 20 with suture 10 pre-attached through the soft tissue 12. Themedial bone anchor 20 may then be moved laterally relative to the bone16 in order to pull the soft tissue 12 laterally relative to the bone16. After appropriate positioning of the soft tissue 12, the medial boneanchor 20 may then be inserted into the bone 16. The lateral bone anchor22 may then be inserted into the bone 16. The suture 12 may then bepassed over the soft tissue 12 and attached to the lateral bone anchor22. In some embodiments, a lateral bone anchor 22 is provided to whichsuture 12 can be attached without tying any knots or without passing thesuture 12 through any aperture in the lateral bone anchor 22.

In some embodiments, multiple anchors and multiple suture lengths mayused to provide a wider area of pressure of the soft tissue againstbone. For example, as depicted in FIG. 3A, three anchors are used withtwo lengths of suture 26 and 28. Alternatively, a mesh structure 29 maybe stretched between the three anchors. In another example, as depictedin FIG. 3B, four anchors are used with two lengths of suture. In stillanother example, as depicted in FIG. 3C, four anchors are used with fourlengths of suture. In some embodiments, the individual suture lengthsmay be part of a larger continuous suture. For example, in FIG. 3A, thesuture lengths 26 and 28 may be part of a larger length of suture suchthat the lengths 26 and 28 are joined at medial bone anchor 20. Those ofskill in the art will appreciate that there are any number of anchor andsuture geometries that can be used.

In some embodiments, the medial bone anchors 20 are designed so thatthey can be easily pierced through the soft tissue 12 and bone 16. Insome embodiments, the lateral bone anchors 22 are designed so that theycan easily capture suture material after insertion of the bone anchors22. Together, these design features provide a suturing system and methodthat provides an increased footprint of suture pressure against the softtissue 12 and ease of implementation for a surgeon. For example, in someembodiments, the entire procedure may be done arthroscopically, with thesurgeon needing only to insert the medial bone anchor 20 with sutureoptionally pre-attached through a first port, insert the lateral anchor22 through a second port, pass the suture over the soft tissue 12 bycapturing it from within the second port, and securing the suture to thelateral anchor 22. Accordingly, described below are certain embodimentsof anchors adapted to capture suture material and anchors adapted toeasily pierce through soft tissue and bone.

Suture Capturing Anchor

One embodiment is a bone anchor that allows easy capturing and securingof a suture after the bone anchor is inserted into the bone. In oneembodiment, the bone anchor includes a suture securing mechanismpositioned on the proximal end of the bone anchor (i.e., the end nearestthe surface of the bone and the surgeon). In one embodiment, the suturesecuring mechanism allows a suture to be moved laterally into themechanism. By “laterally,” it is meant that the suture can be moved intothe mechanism by moving the suture in a direction that is generallyperpendicular to the axis of the suture. In other words, the suture canbe moved into the mechanism without threading an end of the suture intothe mechanism. In one embodiment, the suture can be fixedly securedwithin the mechanism without tying any knots. By “fixedly secured,” itis meant that the suture within the securing mechanism cannot be easilymoved relative to the bone anchor.

One embodiment is a bone anchor that allows easy attachment of suturematerial by clamping the suture material between two surfaces on thebone anchor. The bone anchor may be configured such that the bone anchoris inserted into the bone without the suture material attached. The twosurfaces of the suture securing mechanism may be spaced apart so as toform a gap between the surfaces. The suture material may be passedbetween the two surfaces and tensioned as desired followed by clampingof the two surfaces together, thereby clamping the suture material therebetween.

In one embodiment, the bone anchor consists of two parts: an anchor baseand an anchor top. The anchor base may be designed to be inserted into ahole in the bone with a proximal surface facing up. The anchor top maybe coupled to the anchor base via a distal member. A proximal member onthe anchor top may have a distal surface facing down toward the proximalsurface on the anchor base. The coupling of the anchor top to the anchorbase may be such that the anchor top can move relative to the anchorbase such that it can be positioned in one configuration where there isspace between the proximal surface on the anchor base and the distalsurface on the proximal member of the anchor top. In anotherconfiguration, the proximal member of the anchor top may be positionsuch that there is very little space, if any, between the proximalsurface on the anchor base and the distal surface on the proximal memberof the anchor top. Thus, in the first configuration, suture material maybe easily passed between the two surfaces and tensioned as desired. Inthe second configuration, the suture material may be clamped between thetwo surfaces such that the suture is secured to the bone anchor.

One embodiment of an anchor base 100 is depicted in FIGS. 4A through 4D.FIG. 4A is a perspective view showing the side 101 and bottom 102 of theanchor base 100. The bottom 102 of the anchor base 100 mayadvantageously be tapered to facilitate insertion of the anchor base 100into bone. In some embodiments, a hole is predrilled into the bone tofacilitate insertion of the anchor base 100. In other embodiments, theanchor base 100 is forced directly into the bone, thereby creating thehole. The sides 101 of the anchor base 100 comprise threads 104 so thatthe anchor base 100 may be inserted into bone using a screwing action.In some embodiments, the anchor base 100 may be tapped to start thethreads 104 into the bone followed by screwing the anchor base 100 intothe bone. When the hole in the bone is pre-drilled, the hole isadvantageously drilled with a diameter smaller than the diameter ofthreads 104 so that the threads engage the bone through the sides of thehole. It will be appreciated that means other than threads may be usedto secure the anchor base 100 to bone. For example, angled protrusionsmay be used that provide greater resistance to removal of the anchorbase 100 than to insertion. The protrusions may be static or deployableonce the anchor is inserted.

The top of anchor base 100 preferably includes a structure 106 forfacilitating the driving or screwing of the base 100 into the bone. Inthe illustrated embodiment, this comprises a hex nut structure 106 thatfacilitates engagement with a hex nut driver for screwing the anchorbase 100 into the bone. It will be appreciated that other structuresknown in the art for engaging tools used for screwing action may be usedinstead of hex nut structure 106, and that this structure can beindented into or extending out from the top of the anchor base 100, orcan alternatively be formed on the sides of the anchor base 100.

With reference to FIG. 4B, which is a perspective view of the top andside of anchor base 100, the top (proximal end) comprises a hole 108 inthe center for receiving the anchor top, which is described below. Thetop of anchor base 100 also contains a suture gripping structure such asa circular groove 110 that may be concentric with hole 108. Because ofgroove 110, the proximal surface of anchor base 100 is not flat andcomprises top surfaces 112 and 114, bottom surface 116, and sidesurfaces 118 and 120. In some embodiments, some or all of these surfacesmay be textured such as with a scallop shape or grooves so as to inhibitmovement of suture material pressed against the surfaces. Although agrooved surface is illustrated, it will be appreciated that other shapesfor the proximal surface of anchor base 100 are also contemplated,including multiple concentric grooves, a series of protruding ridges, a“vee” shaped channel, or any other suitable structure that permits asuture to be securely locked against the top or proximal end of theanchor base 100.

Hole 108 in anchor base 100 is an opening into a central (“axial”) boreinto the anchor base 100. The sides of the central bore preferablyinclude structures for gripping something inserted into the centralbore, such as ratchet structures 122. FIG. 4C show a central ratchetbushing 126 that fits within the central bore and contains the ratchetstructures 122. In the embodiment of FIG. 4C, the ratchet structures 122are constructed by cutting U shaped cuts into bushing 126. The U shapedcuts then define tabs that make up the ratchet structures 122. It willbe appreciated that other shapes and methods for making ratchetstructures may be used. The purpose of ratchet bushing 126 is to receivethe anchor top and secure it to the anchor base 100. It will beappreciated that other methods of securing the anchor top to the anchorbase 100 may be used, such as a frictional fit or threading.Furthermore, the anchor top may be coupled to the anchor base 100 usingmeans other than hole 108 and bushing 126. For example, the anchor topmay be coupled via structures at the perimeter rather than the center orby a hinge.

FIG. 4D depicts a cross section through the center of anchor base 100.This view illustrates central bore 130 and groove 110. The proximalsurfaces 112, 114, 116, 118, and 120 are also apparent. Central bore 130preferably does not extend all the way through the anchor base 100.Instead, a smaller bore 132 is present at the distal end 102 of theanchor base 100. Smaller bore 132 is used to receive a wire connected toan anchor inserter. It will be appreciated that other structures thanbore 132 may be used for attaching the wire and that other means than awire may be used to secure the anchor to the anchor inserter.

FIGS. 5A through 5C illustrate one embodiment of an anchor top 200.

FIG. 5A provides a perspective view of the side and top of the anchortop 200 and FIG. 5B provides a perspective view of the side and bottomof the anchor top 200. Anchor top 200 has two members, a distal member202 and a proximal member 204. The distal member 202 comprises anelongated shaft, the longitudinal direction of which shall be consideredto run along the axis of the distal member 202. A series of grooves orother mating or locking surfaces or structures 206 exist along a portionof the outside surface of the shaft. The distal member 202 is designedto be inserted into the central bore 130 of the anchor base 100. Theratchet structures 122 in the anchor base 100 engage grooves 206 tocouple the anchor top 200 to the anchor base 100. The ratchet structures122 are oriented such that the distal member 202 can be easily moved inthe distal direction in central bore 130 with the ratchet structures 122snapping into the grooves 206 as the distal member 202 is moveddownward. However, when the ratchet structures 122 are snapped intogrooves 206, proximal movement of distal member 202 is inhibited. Thus,the anchor top 200 may be ratcheted down into anchor base 100. Becausethe ratchet structures 122 exist along substantially the entire surfaceof the central bore 130 (see FIG. 4C), the anchor top 200 may be coupledto the anchor base 100 in several positions. In other words, in oneembodiment the anchor top 200 need not be ratcheted into the anchor base100 as far as it will go for it to be secured to the anchor base 100.

The proximal member 204 of anchor top 200 is generally cylindrical inshape with a diameter larger than distal member 202. A hole 208 mayadvantageously be provided in the center of proximal member 204. Withreference to FIG. 5B, the bottom of distal member 202 also contains ahole 210. Holes 208 and 210 open into a central bore through the anchortop 200. This central bore allows the wire referred to above to extendthrough the anchor top 200 to be secured to bore 132 in the anchorbottom 100, thus allowing the anchor bottom 100 to be attached to ananchor inserter while still allowing anchor top 200 to be ratchet intoanchor bottom 100. FIG. 5B also illustrates that proximal member 204contains a groove 212 in its distal surface. Thus, the distal surface ofproximal member 204 is not flat and comprises distally facing surfaces214 and 216 and side facing surfaces 218 and 220. In some embodiments,some or all of these surfaces may be textured such as with a scallopshape or grooves so as to inhibit movement of suture material pressedagainst the surfaces. In some embodiments, texturing in the distalsurfaces of proximal member 204 match texturing in the proximal surfacesof anchor base 100. It will be appreciated that the illustratedembodiments represent only one possibility; thus, other shapes for thedistal surface of proximal member 204 may also be used. FIG. 5C depictsa cross section through the center of anchor top 200. In this figure,the central bore 226 is depicted as are surfaces 214, 216, 218, and 220and grooves 206.

FIGS. 6A and 6B depict cross sections showing how the anchor top 200 maybe coupled to anchor base 100 to form the complete anchor 300. In FIG.6A, the anchor top 200 is coupled to anchor base 100 with the proximalmember 204 separated from the anchor base 100. The anchor top 200 issecured to anchor base 100 by distal member 202 extending into centralbore 130 of the anchor base 100. The distal member 202 is secured byratchet structures (not shown) engaging grooves 206 in distal member202. Central bore 226 in anchor top 200 and central bore 130 in anchorbase 100 allow a wire to extend into the top of the anchor 300 and besecured to bore 132. Alternatively, the wire may be secured at otherlocations within central bore 130. Thus the wire, which can be coupledto an anchor inserter, can hold the entire anchor assembly 300 and stillallow anchor top 200 to move relative to anchor base 100 and the wire.

FIG. 6B depicts the anchor assembly 300 with the distal member 202 ofanchor top 200 ratcheted all the way into central bore 130 in anchorbase 100. In this configuration, it can be seen that proximal surfaces112, 114, 116, 118, and 120 of the anchor base 100 and distal surfaces214, 216, 218, and 220 of the proximal member 204 of anchor top 200 formpassageways 302 and 304. The size of passageways 302 and 304 areadvantageously such that when a suture passes through them, it will becompressed so that it is securely attached to the anchor 300.

Another embodiment of the present invention is an inserter designed toinsert and manipulate an anchor such as described in FIGS. 1-3. One suchinserter 400 is depicted in FIGS. 7A and 7B. Inserter 400 comprises ahandle 402 and an outer tube 404. As depicted in FIG. 7A, the handle 402comprises a cover 403. FIG. 7B depicts the inserter 400 with cover 403removed. Not depicted in FIGS. 7A and 7B are an inner tube disposedinside outer tube 404 and a wire disposed within the inner tube. As willbe described in more detail below, the inner and outer tubes may be usedto manipulate an anchor 300 such as that described in FIGS. 4-6. Thewire may be used to couple the inserter 400 to the anchor 300 asdescribed above. Inserter 400 also comprises an outer tube manipulator406 and a wire manipulator 408. Outer tube manipulator 406 comprisesrelease button 410. Outer tube manipulator 406 is securely attached toouter tube 404. Outer tube manipulator 406 may move longitudinallyrelative to handle 402 and the inner tube when release button 410 ispressed. Thus, when outer tube manipulator 406 is moved, outer tube 404also moves.

Wire manipulator 408 comprises wire grabber 410 to which the wire isattached. The wire extends from wire grabber 410, through handle 402,and then through the inner tube. In one embodiment, wire manipulator 408also comprises a release button 412. When release button 412 is pressed,the wire manipulator 408 may be pressed into the handle 402 to contactand thus provide additional tension on the wire. When in use, theadditional tension causes the anchor base 100 to mover relative toinserter 400. When enough tension is provided to the wire by wiremanipulator 408, the wire may break free from the anchor 300 at itsattachment point in bore 132 or at some other predetermined locationalong the wire. It will be appreciated that any suitable breakableattachment means may be used for securing the wire to the anchor 300.For example, the wire may be frictionally secured into bore 132 or itmay welded to the anchor base 100 using a weld that is weaker than thewire itself or a portion of the wire where breaking is desired may beweakened. In one embodiment, the wire is notched so as to create aweaker region in the wire that will break upon application of suitableforce.

The tip 414 of outer tube 404 is depicted in more detail along withinner tube 420, wire 422, and anchor 300 in FIG. 8. The end of outertube 404 may comprise a hex nut driver structure 424 for receiving thehex nut structure 106 of anchor base 100. Of course, any other suitableengagement structure can be provided on the inserter 400 and the anchorbase 100 in order to facilitate placement of the anchor base 100. Wire422 extends out of inner tube 420 and into the central bore in theanchor top 200 to attach to anchor base 100 as described above. In someadvantageous embodiments, the wire length and tension is adjusted suchthat the proximal member 204 of anchor top 200 buts against the end 426of inner tube 420.

FIGS. 9A through 9E depict how inserter 400 and anchor 300 may be usedto insert the anchor 300 into bone and attach a suture to it. FIG. 9Adepicts the configuration for inserting the anchor 300 into bone. Outertube 404 and outer tube manipulator 406 (see FIGS. 7A and 7B) arepositioned relative to inner tube 420 and handle 402 (see FIGS. 7 and 8)so that the outer tube 404 engages hex nut structure 106 in the anchorbase 100. It is advantageous in this configuration for the anchor top200 to be in a position relative to the anchor base 100 such as depictedin FIG. 6A. In the configuration of FIG. 9A, a surgeon may then screwthe anchor base 100 into bone by twisting handle 402 of inserter 400(see FIGS. 7A and 7B).

After the anchor base 100 is inserted into the bone, the outer tube 404may be slid backward relative to the inner tube 420 and handle 402 toexpose the anchor top 200 such as in FIG. 9B. One or more lengths ofsuture 600 may then be placed in the space between the distal surface602 of the proximal member 204 of anchor top 200 and the proximalsurface 604 of the anchor base 100 by moving the suture laterally intothe space as depicted in FIG. 9C. The suture 600 may be manuallytensioned as desired. In some embodiments, tensioning of the suture 600is aided by pulling the suture 600 against the distal member 202 of theanchor top 200.

After appropriate tensioning of suture 600, wire manipulator 408 may bepressed to tension the wire, causing the handle 402 of the inserter 400and the inner tube 420 to be pulled down towards the anchor base 100 sothat inner tube 420 ratchets the anchor top 200 down into the anchorbottom 100 as depicted in FIG. 9D. As the anchor top 200 is pushedaxially down, suture 600 will be clamped between the distal surface 602of the proximal member 204 of anchor top 200 and the proximal surface604 of the anchor base 100 (see also FIG. 9C). The clamping will forcethe suture to be compressed within the passageways 302 and 304 depictedin FIG. 6B and thus be secured to anchor 300. The fit between the anchortop 200 and the anchor base 100 in the clamping region is such that thesuture 600 is firmly gripped, but is not cut, when it is clamped inplace. Appropriate edges that may contact the suture are preferablybeveled or rounded to avoid damage to the suture. After anchor top 200is ratcheted sufficiently into anchor base 100, wire manipulator 408(see FIGS. 7A and 7B) in inserter 400 may be compressed further tofurther tension wire 422 (see FIG. 8) such that wire 422 breaks freefrom its attachment to anchor base 100, thus leaving the anchor 300 freefrom inserter 400 with suture 600 securely attached as depicted in FIG.9E.

Although a particular inserter device for inserting and manipulatinganchor 300 has been described, it should be understood that otherinserter designs may be used for manipulating the parts of anchor 300described above to insert the anchor into bone and secure suturematerial to the anchor. For example, it may be possible to use separatetools for inserting the anchor and securing the suture material. Inaddition, in alternative embodiments, the anchor base 100 may beconnected to the anchor top 200 throughout the procedure, or the anchorbase may be separately inserted into the bone, and the anchor top can beattached thereafter by axially sliding the distal end of the anchor top200 into the hole 108 in the anchor base 100.

It will be appreciated by those of skill in the art that the anchor 300and inserter 400 provide a system for easy attachment of a suture tobone. The anchor 300 may be inserted into bone with minimal disruptionof surrounding tissue. Only an access route having the diameter of theouter tube 404 and the anchor base 100 is required. Furthermore, thesuture can be securely attached to the anchor 300 and tensioned asdesired without having to insert additional instrumentation into thesite or without performing any cumbersome attachment maneuvers such asknot tying. It should also be appreciated that the general principleillustrated by this system of inserting an anchor into bone withouthaving suture material pre-attached and then attaching suture to theanchor without tying any knots may be implemented using any appropriatesystem other than the specific embodiments depicted in FIGS. 4-9.

Tissue and Bone Piercing Anchor

One embodiment is a bone anchor adapted for piercing through the softtissue and into underlying bone. In one embodiment, the suture materialmay be pre-attached to the piercing bone anchor so that afterimplantation, a suture passes from the bone anchor through to the top ofthe soft tissue for easy passing over the soft tissue. In oneembodiment, the piercing bone anchor has two configurations, a firstconfiguration having a small diameter for easy piercing through softtissue and bone and a second deployed configuration where structuressuch as protrusions are deployed to prevent the bone anchor from beingeasily removed from the bone.

In one embodiment, the anchor includes a substantially hollow cylinderhaving a portion of its walls cut in such a manner so as to allow thecylinder to deform under axial stress and form lateral protrusions. Thelateral protrusions may thus prevent the anchor from being easilyremoved from the bone after deployment. In one embodiment, the anchorcomprises a pointed tip coupled to the hollow cylinder for piercing thesoft tissue and bone. In one embodiment, suture is pre-attached to thepointed tip inside of the hollow cylinder. In other embodiments, sutureis pre-attached at other locations on the piercing anchor, such as atthe proximal end of the hollow cylinder.

One embodiment of a deployable piercing anchor is depicted in FIGS. 10Aand 10B. In FIG. 10A, the anchor is depicted in a pre-deployed state.The anchor includes a substantially hollow cylinder 650 with a pluralityof cuts 652 in the side of the cylinder 650. The cylinder 650 is open onone end 654. On the other end, a pointed tip 656 is disposed, allowingthe anchor to pierce through soft tissue and bone. In FIG. 10B, theanchor is depicted in a deployed state. Stress is applied in an axialdirection such that the cylinder 650 collapses along cuts 652 so as toform two lateral wings 660. The lateral wings 660 prevent the anchorfrom being removed from the bone. Hinges 662 connect one end of eachwing to either the top or the bottom parts of anchor body. These hingesdeform and fold, in the plane tangent to the anchor body at that pointwhen the anchor is deployed. A strip of material 664 connects the topand bottom wing on each side of the anchor body, and serves as a hingebetween the two as well as aiding in alignment of the wings duringdeformation. The tips of the wings adjacent to the connecting strip 664utilize rolling edges 666, which ensure uniform alignment and smoothtransition during deformation. Those of skill in the art will appreciatethat any number of geometries of cuts in the cylinder 650 may beutilized to create a deformable structure that will produce lateralprotrusions upon exposure to stress.

In some embodiments, structures may be positioned within the cylinder650 for attaching sutures and engaging with an anchor inserter. In oneembodiment, such structures are coupled to the anchor tip 656 within thecylinder 650. FIG. 11 depicts one such embodiment. Attached to the tip656 is a structure 670 through which there is an aperture 672. Thestructure 670 may be adapted to engage the inner surface of cylinder 650for attaching the tip 656 to the cylinder 650. The attachment mechanismmay be by forced fit, frictional fit, threads, welding, adhesive, or anyother suitable means. Suture material may be threaded through theaperture 672 in order to attach the suture to the anchor. The suturematerial may be secured to the tip 656 by tying the suture aroundstructure 670, tying a knot in the end of the suture that prevents itfrom being pulled through the aperture 672, clamping the suture betweenthe structure 670 and the inside of the cylinder 650, adhering thesuture to structure 670 by welding or adhesive, or any other suitablemeans. In one embodiment, the suture material is attached to the anchorat tip 656 prior to use of the anchor.

An anchor inserter attachment structure 674 may also be coupled to thetip 656. This structure 674 may couple to an anchor inserter through awire or any other suitable means. The attachment between the anchorinserter and the anchor at this point may be used to apply axial stressto the anchor for deploying the anchor as described above. Theattachment at this point may also serve to keep the anchor attached tothe inserter prior to deployment.

One embodiment of an anchor inserter suitable for use with theabove-described anchor is depicted in FIG. 12. The anchor insertercomprises a grasping handle 700 to which is attached an outer sleeve 702which is fixed relative to the handle 700. The piercing anchor 704 isdisposed at the end of the sleeve 702. A deployment lever 706 may bepressed by a user to deploy and detach the anchor 704 as describedbelow. A safety switch 708 may be provided to prevent the anchor 704from being deployed prematurely. A spool 710 may be provided at theproximal end of the handle 700 for holding excess suture. A lid 712 maybe provided for gaining access to the inner components of the inserter.

FIG. 13 depicts the anchor 704 coupled to the inserter. As describedabove, the anchor 704 comprises a hollow cylinder 650 with cuts in thesides and a pointed tip 656. Furthermore, as depicted in FIG. 11, asuture receiving aperture 672 and an inserter attachment structure 674are attached to the pointed tip 656 within the cylinder 650. The outersleeve 702 of the inserter may fit over the open end 654 of the cylinder650 or be flush with the open end 654. The outer sleeve 702 may thushold the top part of the anchor 704 steady during insertion. In analternative embodiment, the outer sleeve 702 may fit over the length ofthe cylinder 650 to prevent the cylinder 650 from deforming while it isbeing inserted into bone. In this alternative embodiment, the outersleeve 702 may be retracted prior to deployment of the anchor. An innertube 720 may be positioned within the outer sleeve 702 and the hollowcylinder 650 and contact the top surface of the anchor tip 656 (see FIG.11). The inner tube 720 provides structural reinforcement of the anchor704 and pushes against the tip of the anchor 704 while it is beingdriven into bone or tissue. The inner tube 720 may be fixed relative tothe handle 712 and outer sleeve 702 during insertion, however, duringdeployment of the anchor 704, the inner tube 720 may be released byswitching safety switch 708 so that the inner tube 720 can move axiallyrelative to the outer sleeve 702 while the anchor cylinder 650collapses. A wire may be positioned inside of the inner tube 720 runningfrom within the handle 712 through the inner tube 720 to the anchor 704and attached to the anchor inserter attachment structure 674. Duringdeployment, the lever 704 may be pressed to pull the wire axiallytowards the handle 700. The axially movement of the wire forces theanchor 704 to press against outer sleeve 702 and stresses the cylinder650, causing it to deform and deploy. During collapse of the cylinder650, the inner tube 720 will also move in an axial direction toward thehandle 700. Upon further stress on the wire, the wire may break freefrom the anchor inserter attachment structure 674, releasing theinserter from the anchor 704. Suture material may run from the inside ofhandle 700 through the inner tube 720 to attach to the anchor 704through aperture 672 (see FIG. 11). Upon detachment of the anchorinserter from the anchor 704, the inserter may be withdrawn, leaving theinserted and deployed anchor with suture coming out of the open end 654of the cylinder 650. The suture will still be coupled to the inserterthrough the inner tube 720, handle 700, and around spool 710. Those ofskill in the art will appreciate other inserters and mechanisms that maybe used to insert and deploy the piercing anchors described herein. Forexample, rather then axially stressing the anchor 704 by pulling the tip656 in an proximal direction, the cylinder 650 may be pushed in a distaldirection to deform the cylinder 650.

FIG. 14 is a cut-away view of the handle 700, showing the inner workingsof the anchor inserter. The suture material attached to a piercinganchor at the tip of the inserter may pass through the central bore ofthe inner tube 720 and through a bore 750 in the handle 700. The suturematerial may then pass through a hole 752 in the end of the handle 700and be wrapped around the spool 710, which may be integral with thehandle 700. The wire attached to the anchor inserter attachmentstructure 674 in the anchor may also pass through the central bore ofthe inner tube 720 and may then proceed around a pulley 754 and attachsecurely to the handle 700 at point 756. The pulley 754 may be attachedto the lever 706. When the lever 706 is pressed down, the pulley 754will move toward the back end of the handle 700, causing the wireattached to the anchor to retract. Because of the use of pulley 754, thewire will retract twice the distance as the pulley 754 moves.

The safety switch 708 may be used to prevent the lever 706 from beingpressed and prevent the inner tube 720 from moving unless the safetyswitch 708 is in the correct position. The safety mechanism operates viaa drum 760 disposed within the handle 700 to which the safety switch 708is attached. Moving the safety switch 708 rotates the drum 760 withinthe handle 700. FIG. 15 shows the drum 760 and safety switch 708mechanism in more detail. The inner tube 720 passes through a centralbore in the drum 760. On the other side of the drum 760, the inner tube720 is attached to a stopper 762. The stopper 762 has a through-hole 764to permit passage of the deployment wire and suture. The stopper 762 maybe positioned within a cavity 766 in the end of the drum 760. A secondsimilarly shaped cavity may be disposed within the handle 700. Thestopper 762 and attached inner tube 720 may only be allowed to moveaxially relative to the handle 700 when the safety switch 708 and drum760 is rotated so that the cavity 766 in the drum 760 is aligned withthe matching cavity in the handle 700. When the cavities are aligned,the stopper 762 is allowed to move from the cavity 766 to the cavity inthe handle 700, thus allowing the inner tube 720 to move axially and theanchor to be deployed.

Additionally, the drum 760 comprises a groove 768. A spring-loadedsliding pin 770 (see FIG. 14) may be coupled to the lever 706. The lever706 can only be moved when the drum 760 and switch 708 are rotated sothat groove 768 is aligned with the pin 770. Thus, both the stopper 764and the pin 770 prevent the anchor from being deployed unless the switch708 is in the correct position.

Those of skill in the art will appreciate other mechanisms that could beused for deploying a deployable anchor and providing safety mechanismsto prevent premature deployment.

Example Using a Piercing Anchor and a Suture Capturing Anchor

The above-described anchors may be used in a surgical procedure forattaching soft tissue to bone. One example of such a procedure isdepicted in FIGS. 16A through 16F. In FIG. 16A, the piercing anchor 800attached to an anchor inserter 802 as described above is pierced throughsoft tissue 804 that has become detached from underlying bone 806. InFIG. 16B, the anchor inserter 802 is moved laterally relative to thebone 806 so as to stretch the soft tissue 804 laterally relative to thebone 806. Once the soft tissue 804 has been stretched to the desiredposition, the anchor 800 is inserted into the bone 806 and the anchor800 is deployed as described above and the inserter 802 is detached fromthe anchor 800, leaving a suture 808 attached to the anchor 800 andextending through the soft tissue 804. The anchor 800 may be insertedinto bone 806 by tapping on the inserter 802 with a hammer or by anyother suitable means of applying axial force. FIG. 16C depicts thedeployed anchor 800 with attached suture 808. The suture 808 will extendinto the inserter 802.

Next, as depicted in FIG. 16D, a suture capturing anchor 810 is insertedinto the bone 806 using the inserter 812 as described above. In FIG.16E, the inserter 812 is then retracted to expose the suture capturingmechanism. The suture 808 is then passed over the soft tissue 804 andlaterally moved into the suture capturing mechanism and tensioned.Finally, as depicted in FIG. 16F, the suture capturing mechanism isdeployed to capture the suture 808, the anchor inserter 812 is detachedfrom the anchor 810, and the suture 808 is cut to detach it from thesuture inserter 802. The result is a length of suture 808 between thebone anchors 808 and 810 that presses the soft tissue 804 against thebone 806. Multiple anchors and sutures may be used to produce geometriessuch as depicted in FIGS. 2 and 3 and variations thereof.

It will be appreciated that there are numerous stitches, suturethreading patterns, and anchor patterns that may be used to secure softtissue to bone by the methods and devices described herein. Thesevariations as well as variations in the design of the above describedanchor devices and inserter devices are within the scope of the presentdisclosure.

Methods of Attaching Soft Tissue to Bone

Various embodiments include methods for attaching soft tissue to bone.In some embodiments, the methods include using the bone anchorsdescribed above. In one embodiment, a bone anchor is inserted into thebone and then a length of suture is passed over the soft tissue andsecured to the anchor after inserting the anchor without tying any knotsor without passing the suture through an aperture in the anchor. In someembodiments, the suture is secured to the anchor by laterally moving itinto a securing mechanism. In one embodiment, securing the suture to theanchor includes clamping the suture between at least two surfaces on theanchor. In one embodiment, the anchor is not inserted further into thebone after securing the suture to it.

In another embodiment, a first anchor with a suture pre-attached isinserted through the soft tissue and into the bone. The suture may thenbe passed over the soft tissue and fixedly secured to a second boneanchor. In one embodiment, the first anchor is inserted by directlypiercing the soft tissue and the bone. In one embodiment, lateralprotrusion may be deployed on the first anchor to prevent the firstanchor from being removed. In one embodiment, the suture may be coupledto the second bone anchor prior to insertion and then fixedly securedafter insertion. In this context, “coupled” means that the suture isattached to the bone anchor but not fixedly secured, such that thesuture can move to some extent relative to the bone anchor. In analternative embodiment, the suture is not coupled to the second boneanchor during its insertion.

In another embodiment, a first portion of suture is inserted into theproximal surface of the soft tissue. A second portion of the suture(e.g., the portion proximal to the inserted portion) is then passed overthe proximal surface of the soft tissue and fixedly secured to a boneanchor. In one embodiment, the procedure may be performed withoutpassing the first portion of the suture back out of the proximal surfaceof the soft tissue. In one embodiment, this result is accomplished bythe first portion of the suture being attached to an anchor that isinserted through the soft tissue and into bone.

One embodiment includes inserting a first anchor with a pre-coupledsuture through soft tissue and into bone. The suture may then be passedover the soft tissue and fixedly secured to a second anchor. In oneembodiment, the pre-coupled suture is fixedly secured to the firstanchor prior to insertion. In an alternative embodiment, the pre-coupledsuture can move relative to the first anchor prior to insertion and isfixedly secured after insertion.

In another embodiment, multiple lengths of suture are attached tomultiple anchors. In one embodiment at least three anchors are insertedinto bone. A first length of suture may be secured between a first andsecond anchor and a second length of suture may be secured between thefirst and a third anchor. In one embodiment, the first anchor ispositioned beneath the soft tissue and the second and third anchors arepositioned laterally to the soft tissue. In an alternative embodiment,the first anchor is positioned laterally to the soft tissue and thesecond and third anchors are positioned beneath the soft tissue. In someembodiments, the lengths of suture are fixedly secured to the anchor(s)positioned beneath the soft tissue prior to insertion of thoseanchor(s). In one embodiment, the different lengths of suture may betensioned separately.

In various embodiments, prior to fixedly securing suture to a boneanchor, it can be tensioned. In one embodiment, tensioning isaccomplished by manually pulling on the suture such as by a surgeongrasping the suture using an appropriate instrument and then pulling. Inone embodiment, the suture may be pressed against the bone anchor toprovide leverage for pulling. For example, the suture may be wrappedpartly around a proximal portion of the anchor prior to pulling.

Although the invention has been described with reference to embodimentsand examples, it should be understood that numerous and variousmodifications can be made without departing from the spirit of theinvention. Accordingly, the invention is limited only by the followingclaims.

What is claimed is:
 1. An anchor for securing a suture to bone, saidanchor comprising: a substantially hollow cylinder comprising an openend and comprising a portion of its walls cut in such a manner so as toallow the cylinder to deform under stress and form lateral protrusions;a substantially pointed tip coupled to the cylinder opposite the openend, wherein the pointed tip is adapted to pierce the bone; and a suturereceiver coupled to said pointed tip and positioned so that a suture maybe attached to the suture receiver and extend longitudinally through thecylinder and out of the open end.
 2. The anchor of claim 1, wherein thelateral protrusions consist of two protrusions opposite each other. 3.The anchor of claim 1, further comprising a stress inducing membercoupled to the tip and extending through the cylinder and out of theopen end, wherein the cylinder is adapted to deform when force isapplied to pull the stress inducing member proximally out of thecylinder.
 4. The anchor of claim 3, wherein after the cylinder hasdeformed, the stress inducing member is adapted to break free from thetip upon continued application of force.
 5. The anchor of claim 3,wherein the stress inducing member is a wire.
 6. The anchor of claim 1,wherein the suture receiver comprises an eyelet.
 7. The anchor of claim1, wherein the pointed tip is affixed to the cylinder.
 8. The anchor ofclaim 1, wherein the pointed tip is integrally formed in the cylinder.9. The anchor of claim 1, wherein the suture receiver is proximate tothe pointed tip.
 10. The anchor of claim 9, wherein the suture receiveris integral in the pointed tip.
 11. A bone anchor, comprising: acylindrical body having cuts formed in its side such that the body candeform under axial force to form one or more lateral features, whereinat least some of the cuts define two convex edges adapted tocontinuously roll against each other during deformation; and a suturereceiver positioned so that a suture may be attached to the suturereceiver and extend longitudinally through the cylinder.
 12. The anchorof claim 11, comprising a substantially pointed tip positioned on afirst end of the cylindrical body.
 13. The anchor of claim 12,comprising a suture attached to the tip and extending through thecylindrical body and out a second end of the cylindrical body that isopposite the first end.
 14. The anchor of claim 13, configured to formtwo lateral features after deformation.
 15. The anchor of claim 13,wherein at least some of the cuts define an upper and lower portion ofone of the lateral features and wherein one of the convex edges is anedge of the upper portion of the lateral feature and the other convexedge is an edge of the lower portion of the lateral feature.
 16. A boneanchor, comprising a substantially hollow cylindrical body having anopen end and a substantially pointed tip comprising a suture receiverpositioned opposite the open end, the substantially hollow cylindricalbody having cuts formed in its side such that the body can deform underaxial force to form one or more lateral features, wherein at least someof the cuts define one or more hinges about which a first portion of theside of the body can bend during deformation and define an edge of saidfirst portion adapted to contact a second portion of the side of thebody, wherein said first portion forms part of one of the lateralfeatures after deformation, wherein a suture may be attached to thesuture receiver and extend longitudinally through the cylinder and outof the open end.
 17. The anchor of claim 16, wherein said first portionand said second portion are connected to each other through the hinges.18. The anchor of claim 16, wherein the first portion forms a lowerportion of one of the lateral features.
 19. The anchor of claim 16,wherein the second portion comprises a part of the cylindrical body thatis uncut around its circumference.
 20. The anchor of claim 16, whereinthe second portion comprises a part of the cylindrical body that doesnot deform under the axial force that forms the one or more lateralfeatures.
 21. The anchor of claim 16, comprising a substantially pointedtip positioned on a first end of the cylindrical body.
 22. The anchor ofclaim 21, comprising a suture attached to the tip and extending throughthe cylindrical body and out a second end of the cylindrical body thatis opposite the first end.
 23. The anchor of claim 21, wherein the tipis attached to the second portion.
 24. A bone anchor, comprising: asubstantially hollow cylinder comprising a plurality of cuts in the sideof the cylinder configured to allow the cylinder to deform under stressand comprising a proximal open end and a distal open end; and a pointedtip comprising a suture receiver positioned so that a suture may beattached to the suture receiver and extend longitudinally through thecylinder and out of the proximal open end, wherein the pointed tip isconfigured to pierce a bone and connect to the suture receiver, whereinthe pointed tip is attached to the distal open end of the substantiallyhollow cylinder.
 25. The bone anchor of claim 24, wherein at least someof the cuts in the side of the cylinder are longitudinal.
 26. The boneanchor of claim 24, wherein at least some of the cuts define two convexedges adapted to continuously roll against each other throughoutdeformation.
 27. The bone anchor of claim 24, wherein at least some ofthe longitudinal cuts define an axially aligned connecting stripconfigured to define a hinge between a first portion of thesubstantially hollow cylinder and a second portion of the substantiallyhollow cylinder.
 28. The bone anchor of claim 27, where the firstportion of the substantially hollow cylinder can displace duringdeformation of the cylinder to form part of a lateral feature.
 29. Theanchor of claim 24, wherein the pointed tip is affixed to the cylinder.30. The anchor of claim 24, wherein the pointed tip is integrally formedin the cylinder.
 31. The anchor of claim 24, wherein the suture receiveris integrally formed in the pointed tip.
 32. The anchor of claim 24,wherein the suture receiver is affixed to the pointed tip.
 33. Theanchor of claim 24, wherein the suture longitudinally extends throughthe substantially hollow cylinder.